I always thought that Lump burned hotter, and Briquettes seemed to clog themselves with ashes after a 5 hours or so(hence the uds bang/wiggle rod mod). I would have thought that the ash factor was the main contiributor, and that Lump would be more constant.
However, I have seen some folks who hand assemble the lump pieces so the burn it ultra consistent . . .
Will watch for more responses.